The invention generally relates to systems for treatment of the spine, and more particularly to systems for placement of stabilization devices on the spine.
It is desirable to maintain the positioning of a stabilization device, such as a plate, before and during attachment of it to the spine. Instruments have been provided to grasp the stabilization device so that it can be remotely held in the desired position during attachment. However, such instruments can obstruct access to the stabilization device, while also occupying space in the surgical site and/or in the approach to the surgical site, hindering attachment of the device to the spine.
Elongated spinal plates have been temporarily secured to the spine with a bone screw positioned through one or more bone screw openings in the plate. This technique, however, requires additional steps since the temporary screw must be removed from the plate for placement of the final bone screw at the proper angle and depth through the plate. Also, the temporary screw limits the order of placement of bone screws through the plate openings. Still further, the temporary screw creates a bore in the bone underlying the plate opening that may not be oriented at the desired angle relative to the plate, making it more difficult to create a bore at the desired angle and/or hindering or preventing the placement of self-drilling or self-tapping screws.
Other elongated plates include holes in addition to the bone screw openings to receive temporary fixation devices therethrough to temporarily secure the plate to the spine. However, these additional holes through the plate provide areas of reduced plate strength, or require the plate size to be increased to compensate for the loss of strength. Still further, these extra holes increase the “fiddle factor” since additional steps are required for placement and removal of temporary fixation devices in these holes in addition to those steps normally required to finally secure the plate to the spine.
Elongated plates can also include devices that prevent bone screws from backing out relative to the plate after it is secured to the spine. The difficulty of revision surgery can be increased when tissue or other bioactivity blocks and/or impedes access to these devices and the bones screws extending through the plate.
Thus, there is a need to provide improved systems and techniques for attaching stabilization devices to the spine and for facilitating revision surgery.